1. Field of the Invention
The present invention relates to a ratchet wrench having a rigid locking structure, and more particularly to a ratchet wrench having a rigid locking structure, wherein the support blocks of the pawl member are urged on the wall of the receiving chamber of the wrench body, thereby forming a double-support or multi-support structure between the pawl member and the wall of the receiving chamber of the wrench body, so that the locking teeth of the pawl member are engaged with the ratchet teeth of the ratchet wheel actually, closely, rigidly and stably.
2. Description of the Related Art
A conventional ratchet wrench in accordance with the prior art shown in FIGS. 6 and 7 comprises a wrench body 90, a ratchet wheel 93, a pawl member 95, and a restoring member 96. The wrench body 90 has a driving head 91 having an inner wall formed with a receiving recess 92 and a receiving chamber 94. The ratchet wheel 93 is mounted in the receiving recess 92 of the driving head 91 of the wrench body 90 and has an outer wall formed with a plurality of ratchet teeth 930. The pawl member 95 is mounted in the receiving chamber 94 of the wrench body 90 and has a first side formed with a plurality of locking teeth 950 engaged with the ratchet teeth 930 of the ratchet wheel 93 and a second side formed with an arcuate resting face 97. The restoring member 96 is mounted in the receiving chamber 94 of the wrench body 90 and urged between the pawl member 95 and the wall of the receiving chamber 94 of the wrench body 90. Thus, a support force xe2x80x9cFxe2x80x9d is formed between the arcuate resting face 97 of the pawl member 95 and the wall of the receiving chamber 94 of the wrench body 90.
As shown in FIG. 6, the contact position of the arcuate resting face 97 of the pawl member 95 and the wall of the receiving chamber 94 of the wrench body 90 is located at the left end of the pawl member 95.
As shown in FIG. 7, the contact position of the arcuate resting face 97 of the pawl member 95 and the wall of the receiving chamber 94 of the wrench body 90 is located at the mediate portion of the pawl member 95.
However, the conventional ratchet wrench in accordance with the prior art has the following disadvantages.
1. The contact position of the arcuate resting face 97 of the pawl member 95 and the wall of the receiving chamber 94 of the wrench body 90 deflects and deviates as shown in FIGS. 6 and 7, so that the pawl member 95 is not engaged with the ratchet wheel 93 closely, rigidly and stably.
2. The contact position of the arcuate resting face 97 of the pawl member 95 and the wall of the receiving chamber 94 of the wrench body 90 is almost a point, thereby producing a stress concentration on the wall of the receiving chamber 94 of the wrench body 90, and thereby decreasing the lifetime of the ratchet wrench.
3. The contact position of the arcuate resting face 97 of the pawl member 95 and the wall of the receiving chamber 94 of the wrench body 90 is almost a point, thereby decreasing the torque of the ratchet wrench.
The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional ratchet wrench.
The primary objective of the present invention is to provide a ratchet wrench having a rigid locking structure, wherein the support blocks of the pawl member are urged on the wall of the receiving chamber of the wrench body, thereby forming a double-support or multi-support structure between the pawl member and the wall of the receiving chamber of the wrench body, so that the locking teeth of the pawl member are engaged with the ratchet teeth of the ratchet wheel actually, closely, rigidly and stably.
Another objective of the present invention is to provide a ratchet wrench having a rigid locking structure, wherein the multiple support forces evenly support the pawl member, thereby preventing from producing a stress concentration on the wall of the receiving chamber of the wrench body, so that the pawl member is locked with the ratchet wheel actually and stably without slip or detachment.
A further objective of the present invention is to provide a ratchet wrench having a rigid locking structure, wherein the multiple support forces produce a larger force resistant area between the pawl member and the wall of the receiving chamber of the wrench body, thereby increasing the efficient torque of the ratchet wrench.
A further objective of the present invention is to provide a ratchet wrench having a rigid locking structure, wherein the multiple support forces evenly support the pawl member, thereby producing a larger force resistant area, and thereby preventing from producing a stress concentration on the wall of the receiving chamber of the wrench body, so as to increase the lifetime of the ratchet wrench.
A further objective of the present invention is to provide a ratchet wrench having a rigid locking structure, wherein the multiple support blocks evenly support the pawl member, so that the pawl member is moved on the wall of the receiving chamber of the wrench body smoothly and conveniently and is engaged with the ratchet wheel rapidly and rigidly, thereby facilitating the user operating the ratchet wrench.
In accordance with the present invention, there is provided a ratchet wrench having a rigid locking structure, comprising a wrench body, a ratchet wheel, a pawl member, and a restoring member, wherein:
the wrench body has a driving head having an inner wall formed with a receiving recess and a receiving chamber located beside and communicated with the receiving recess;
the ratchet wheel is mounted in the receiving recess of the driving head of the wrench body and has an outer wall formed with a plurality of ratchet teeth;
the pawl member is mounted in the receiving chamber of the driving head of the wrench body and has a first side formed with a plurality of locking teeth engaged with the ratchet teeth of the ratchet wheel and a second side formed with a plurality of convex support blocks each rested on a wall of the receiving chamber of the driving head of the wrench body;
the restoring member is mounted in the receiving chamber of the driving head of the wrench body and urged between the pawl member and the wall of the receiving chamber of the driving head of the wrench body.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.